viced: Ignore client loopback alternate addresses

viced: Ignore client loopback alternate addresses

When we receive interface information from a client to determine its
alternate IP addresses, ignore any addresses that look like loopback.

Change-Id: I245ebfc74ad1e8bd2fcd235a00f000d29229668d
Reviewed-on: http://gerrit.openafs.org/2368
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>